Reclining Buddha at Gal Vihara, Sri Lanka. The remains of the image house that originally enclosed it can be seen.

Petroglyphs are images created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images. Petroglyphs are found worldwide, and are often associated with prehistoric peoples. The word comes from the Greek word petro-, theme of the word "petra" meaning "stone", and glyphein meaning "to carve", and was originally coined in French as pétroglyphe.

The term petroglyph should not be confused with petrograph, which is an image drawn or painted on a rock face. Both types of image belong to the wider and more general category of rock art or parietal art. Petroforms, or patterns and shapes made by many large rocks and boulders over the ground, are also quite different. Inukshuks are also unique, and found only in the Arctic (except for reproductions and imitations built in more southerly latitudes).

A more developed form of petroglyph, normally found in literate cultures, a rock relief or rock-cut relief is a relief sculpture carved on solid or "living rock" such as a cliff, rather than a detached piece of stone. They are a category of rock art, and sometimes found in conjunction with rock-cut architecture.[1] However, they tend to be omitted in most works on rock art, which concentrate on engravings and paintings by prehistoric peoples. A few such works exploit the natural contours of the rock and use them to define an image, but they do not amount to man-made reliefs. Rock reliefs have been made in many cultures, and were especially important in the art of the Ancient Near East.[2] Rock reliefs are generally fairly large, as they need to be to make an impact in the open air. Most have figures that are over life-size, and in many the figures are multiples of life-size.

Stylistically they normally relate to other types of sculpture from the culture and period concerned, and except for Hittite and Persian examples they are generally discussed as part of that wider subject.[3] The vertical relief is most common, but reliefs on essentially horizontal surfaces are also found. The term typically excludes relief carvings inside caves, whether natural or themselves man-made, which are especially found in India. Natural rock formations made into statues or other sculpture in the round, most famously at the Great Sphinx of Giza, are also usually excluded. Reliefs on large boulders left in their natural location, like the Hittite İmamkullu relief, are likely to be included, but smaller boulders may be called stele or carved orthostats.

Some petroglyphs are dated to approximately the Neolithic and late Upper Paleolithic boundary, about 10,000 to 12,000 years ago, if not earlier (Kamyana Mohyla). Sites in Australia have petroglyphs that are estimated to be as much as 27,000 years old, and in other places could be as old as 40,000 years. Around 7,000 to 9,000 years ago, other precursors of writing systems, such as pictographs and ideograms, began to appear. Petroglyphs were still common though, and some cultures continued using them much longer, even until contact with Western culture was made in the 20th century. Petroglyphs have been found in all parts of the globe except Antarctica with highest concentrations in parts of Africa, Scandinavia, Siberia, southwestern North America and Australia.

There are many theories to explain their purpose, depending on their location, age, and the type of image. Some petroglyphs are thought to be astronomical markers, maps, and other forms of symbolic communication, including a form of "proto-writing". Petroglyph maps may show trails, symbols communicating time and distances traveled, as well as the local terrain in the form of rivers, landforms and other geographic features. A petroglyph that represents a landform or the surrounding terrain is known as a geocontourglyph. They might also have been a by-product of other rituals: sites in India, for example, have been identified as musical instruments or "rock gongs".[4]

Some petroglyph images probably have deep cultural and religious significance for the societies that created them; in many cases this significance remains for their descendants. Many petroglyphs are thought to represent some kind of not-yet-fully understood symbolic or ritual language. Later glyphs from the Nordic Bronze Age in Scandinavia seem to refer to some form of territorial boundary between tribes, in addition to possible religious meanings. It also appears that local or regional dialects from similar or neighboring peoples exist. The Siberian inscriptions look similar to an early form of runes, although there is not thought to be any relationship between them. They are not yet well understood.

Some researchers have noticed the resemblance of different styles of petroglyphs across different continents; while it is expected that all people would be inspired by their surroundings, it is harder to explain the common styles. This could be mere coincidence, an indication that certain groups of people migrated widely from some initial common area, or indication of a common origin. In 1853, George Tate read a paper to the Berwick Naturalists' Club, at which a John Collingwood Bruce agreed that the carvings had "... a common origin, and indicate a symbolic meaning, representing some popular thought."[5] In his cataloguing of Scottish rock art, Ronald Morris summarised 104 different theories on their interpretation.[6]

Present-day links between shamanism and rock art amongst the San people of the Kalahari desert have been studied by the Rock Art Research Institute (RARI) of the University of the Witwatersrand.[10] Though the San people's artworks are predominantly paintings, the beliefs behind them can perhaps be used as a basis for understanding other types of rock art, including petroglyphs. To quote from the RARI website:

Using knowledge of San beliefs, researchers have shown that the art played a fundamental part in the religious lives of its San painters. The art captured things from the San's world behind the rock-face: the other world inhabited by spirit creatures, to which dancers could travel in animal form, and where people of ecstasy could draw power and bring it back for healing, rain-making and capturing the game.

Wadi Hammamat in Qift, many carvings and inscriptions dating from before the earliest Egyptian Dynasties to the modern era, including the only painted petroglyph known from the Eastern Desert and drawings of Egyptian reed boats dated to 4000 BCE

Inscription Rock in South Sinai, is a large rock with carvings and writings ranging from Nabatean to Latin, Ancient Greek and Crusder eras located a few miles from the Ain Hudra Oasis. There is also a second rock approximately 1 km from the main rock near the Nabatean tombs of Nawamis with carvings of animals including Camels, Gazelles and others. The original archaeologists who investigated these in the 1800s have also left their names carved on this rock.

Giraffe petroglyphs found in the region of Gebel el-Silsila. The rock faces have been used for extensive quarrying of materials for temple building especially during the period specified as the New Kingdom. The Giraffe depictions are located near a stela of the king Amenhotep IV. The images are not dated, but they are probably dated from the Predynastic periods.

Recently petroglyphs were found at Kollur village in Tamil Nadu. A large dolmen with four petroglyphs that portray men with trident and a wheel with spokes has been found at Kollur near Triukoilur 35 km from Villupuram. The discovery was made by K.T. Gandhirajan. This is the second instance when a dolmen with petrographs has been found in Tamil Nadu, India.[15]

During recent years a large number of rock carvings has been identified in different parts of Iran. The vast majority depict the ibex.[16][17] Rock drawings were found in December 2016 near Khomeyn, Iran, which may be the oldest drawings discovered, with one cluster possibly 40,000 years old. Accurate estimations were unavailable due to US sanctions.[18]

Petroglyphs are the most ancient works of art left by human kind that secretly provide an opening to the past eras of life and help us to discover different aspects of prehistoric lives. Tools to create petroglyphs can be classified by the age and the historical era; they could be flint, thighbone of hunted quarries, or metallic tools. The oldest Pictographs in Iran are seen in Yafteh cave in Lorestan that date back 40000 and the oldest petroglyph discovered belongs to Timareh dating back to 40800 years ago.

Pictograph of lorestan (koohdasht) 10000 BCE

Iran provides exclusive demonstrations of script formation from pictogram, ideogram, linear (2300 BC) or proto Elamite, geometric old Elamite script, Pahlevi script, Arabic script (906 years ago), Kufi script, and Farsi script back to at least 250 years ago. More than 50000 petroglyphs have been discovered, extended over all Iran's states.[19]

Curious boy sitting near petroglyphs

Petroglyphs in Iran follow the same general categorization:

1-Pictographs that contain pictures drawn by pigments like smut, crystalized blood, ocher, that were employed by binders like animal fats, blood, seed oil and organic compounds or a mixture of all materials mentioned above. Lorestan has the most and oldest pictographs in Iran. Yafteh cave in Lorestan has pictographs dating back to 40000 years ago.Compared to petroglyphs, pictographs in Iran are scarce and rare.Sites that contain pictographs are listed as follows:

The most recent chronology of petroglyphs in Iran was done employing the General Accelerator Spectrometer in 2008 that helped gather data from random samples; though, this is a demanding job that needs a systematic and comprehensive supported effort.

The following table offers the first classification of petroglyphs according to redundancy and frequency

The theme occurrence of petroglyphs by random sampling( percentage )

percentage

carvings

number

88

Ibex, symbolically depicted by a long curved horn that extends to tail.

1

3

Human figures as in rituals, roping [cattles], using arches on the back of the horses or on-foot, hunting dressed or not and etc…

One of the characteristics of Iran’s petroglyphs is the continuity of existence of prehistoric marks on the ancient potteries and bronze sculptures that reveal the impressiveness of petroglyphs of the facades of caves and rocks reflected on ancient work of arts.

This continuity can be traced from eighth millennium BC by the potteries in Ganj Darreh near Harseen in Kermanshah state, to third and first millennium BC , considering the bronze period in Lorestan. There is a unique similarity between petroglyph marks and prehistoric potteries as if all these works are done by a sole artist.

The oldest reliably dated rock art in the Americas is known as the "Horny Little Man." It is petroglyph depicting a stick figure with an oversized phallus and carved in Lapa do Santo, a cave in central-eastern Brazil and dates from 12,000 to 9,000 years ago.[28]

Modern Hopi have interpreted the petroglyphs at Mesa Verde National Park's Petroglyph Point as depictions of the Eagle, Mountain Sheep, Parrot, Horned Toad, and Mountain Lion clans, and the Ancestral Puebloans who inhabited the mesa